|
General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
|
Thread Tools |
2nd Feb 2004, 1:12 pm | #1 |
Hexode
Join Date: Mar 2003
Location: World Heritage Village of Saltaire, Shipley, West Riding of Yorkshire.
Posts: 324
|
Capacitors kept in stock
Just wondered what is the smallest number of capacitors one would need to keep in stock, to be able to repair the majority of radios. I have a lot of mixed voltage/value capacitors in stock, but you never seem to have the one you are looking for. Bearing in mind that the Tolerance can be anything from 10% to 50% +/-, how many values do I need to keep in stock?
I am sure my Ham friend in past days would have kept the Capacitors/Resistors he was going to require in stock without having to order each time he repaired a radio. Paul E |
2nd Feb 2004, 3:37 pm | #2 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,966
|
Re: Capacitors kept in stock
In most cases you can get away with subbing a substantially larger cap than the original. Radio designers used the smallest capacitance that would work in a particular circuit, since these were cheaper if only by a penny or two. Apart from tone correction caps, you could probably change all the wax caps in the audio section of a radio with 0.1uF 400V jobs. I'm not actually advocating this but you don't need to keep a full range of every single standard value.
The low value wax caps in the RF sections are usually fine and best left alone. With regard to electrolytics, 33uF 450V will do practically everything - smoothing, decoupling etc. Again, a wider range is desirable, but not essential. My stock of caps is determined by 2 factors: 1. What I've bought from eBay. I bought 200 .0047uF 400V polyester caps from a guy last year for £2. I won't be running out of those in a hurry. 2. What I've remembered to order from Mouser recently. I never order enough, since the component prices are low and the $6-8 shipping charge is often a significant part of the order. Best regards, Paul |
2nd Feb 2004, 6:04 pm | #3 |
Retired Dormant Member
Join Date: Jan 2003
Location: Livermore, California, USA.
Posts: 139
|
Re: Capacitors kept in stock
Hi
Agree with Paul, you don't need a lot of values. I would only stock 600 (630) volt rated caps. These will replace any cap up to this voltage rating. Having .001, .01 and .1 MFD will cover cover most requirements. US radios also used a lot of .02 & .05 MFD caps. 10 MFD @ 450 volts covers most filter cap requirements of old radios. I also keep some 22 MFD @ 450 volt caps. For AC/DC radios in the US 33 & 47 MFD @ 160 volts will cover most needs. In UK you may need higher voltage rated electrolytic caps? Norm |